Mell's keystone

 is an item in Bastard's Wound.

Description
A simple yellow keystone, used by Bastard Wounders to gain access to teleporters.

Location

 * Bastard's Wound: Received from Mell during Gambler's Ruin.
 * Note that if you start Midnight Wanderer without fully resolving Gambler's Ruin, Insipid Moniker will pocket this keystone as she uses her own keystone. To get back Mell's keystone, you must talk to her.